random: TPM_HARVEST should have been named RANDOM_ENABLE_TPM

• Enable RANDOM_ENABLE_TPM by default

• The commit of TPM_HARVEST failed to add it to NOTES so that the LINT kernel would build the code.

Fixes: 4ee7d3b0118c82e651712bb65da53d08e78cd7b1
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D53460